What is the TCP/IP Model?

Just like human beings talk with each other. Computers also need to have a common way to communicate with each other. Today, most computers use the TCP/IP model or standards for network communications.

Computers are so powerful that they can do many jobs quickly. Computers’ original or proper shine comes when they communicate with each other- whether these activities are chatting, sending email watching content on OTT platforms such as Netflix, Hotstar, etc.

Today, over 8 billion devices are connected to the internet using this Tcp/Ip model, most of which fit in the user’s pocket. The creation and mass acquisition of the World Wide Web is the most significant human accomplishment of all time.

With the internet, ideas can be shared from any place,24*7, by anyone with a connection. Limits for geographic communication stand no more at this time.

What is a Network Protocol?

A Network protocol does not straightforwardly define how devices and processes will work. They define how devices and processes will work jointly. Without these fixed conventions and rules, the Internet would lack the infrastructure that it needs to be functional and operational. Network protocols are the foundation of present-day communications, without which the digital world could not stand.

Without protocols, devices wouldn’t be able to acknowledge the electronic signals they send to each other over network connections.

Modern protocols for computer networking use packet-switching techniques to send and receive messages in the form of packets, where messages are broken down into pieces that are collected and reconstructed at their destination. Many compatible computer network protocols have emerged, each developed for specific purposes and environments.

A network protocol includes all the regulations and conventions for communication between network gadgets or devices, including ways to identify and connect with everyone. There are also formatting rules that describe how data is packaged into sent and received messages.

Internet Protocols

The Internet Protocol (IP) family contains a set of related and popular network protocols. Besides the Internet Protocol, distinguished protocols such as TCP, UDP, HTTP, and FTP merge with IP to provide additional capabilities.

TCP/IP stands for Transmission Control Protocol/ Internet Protocol. It was developed by the Department of Defense (DoD) in the 1960s. The TCP/Ip model is a compact version of the OSI model. It consists of 5 layers compared to OSI models, which have seven layers.TCP and IP are two independent computer network protocols. IP is the part that obtains the address to which data is sent. TCP manages data delivery once that IP address has been found. Think of it this way.

The IP address is like a phone number the telecom company provides us. TCP is all the technology that makes the phone ring, which enables us to talk to someone on another phone. They are different from one another, but they are also worthless without one another.

The OSI model describes network communications with a family of protocols. TCP/IP does not belong to this model directly. The TCP/IP model combines several OSI layers into a single layer.

TCP/Ip Model Layers:

We need to provide the basic information required by TCP/IP in a standard format the network can understand. This format is supported by its five-layer software model.

Each layer provides TCP/IP with the elementary information that needs to move our data across the network. These layers group functions according to the task that needs to be executed. Each layer in this model is aimed to help a specific layer that performs its job. Each layer only communicates with adjoining layers.

1. Physical Layer is the transceiver that drives the signal on the network.

2. Data Link Layer(MAC) creates the frames that move across the network.

3. Network Layer(IP) is responsible for creating the packets that move across the network.

4. Transport Layer helps establish connections b/w applications on different host machines.

5. Application Layer is a group of applications that require network communications.

Now that we know each layer’s main job let’s see how they work together to send and receive data across a TCP/IP network.

This is a simplified view of how the network layers work cooperatively to generate frames. Higher layers pass information to the bottom layers. Each layer adds information called a header to the data(or message) being passed to it. This header consists of information the layer needs to perform its job.

Application Layer

The Application layer initiates a message. Mostly the specific application is a web browser requesting a webpage download. This message is then sent or forwarded to the Transport layer.

Transport Layer

The Transport layer adds the TCP or UDP header comprising the source and destination port addresses. Supplementary information like the packet sequence number used for TCP will also be added to the header. The data generated by the transport layer is referred to as a Segment or fragment if TCP is used and is referred to as a Datagram if UDP is used. This segment is then sent to the Network layer.

Network Layer

The Network layer attaches a header, including the source and destination IP address, to generate a packet. This packet is then sent to the Data Link layer.

Data Link Layer

The Data Link layer attaches a header containing the MAC address information to create a frame. The frame is then conveyed to the Physical layer to transmit the bits.

The Five Layer Services

ApplicationProcess-process Communication
TransportLogical communication, segment-level error detection/correction, guaranteed delivery
NetworkHost-host communication, data fragmentation, best delivery effort
Data LinkNode-node communication, bit-level error detection/correction, best delivery effort
PhysicalBit-level data delivery

The Five Layer: Protocols

NetworkIP, ICMP, ARP
Data LinkARP, MAC (Ethernet, DSL)
PhysicalRZ, Manchester, Differential Manchester, ASK, FSK

The Five Layers: Addressing

ApplicationProcess Id
TransportPort Number
NetworkIp Address
LinkMAC address

Real-Time Applications based on TCP/Ip Model

There are various real-time applications of TCP/IP that even most people do not know of this. They are already using those applications but lack the concept behind them. Some of them are:

➔File Transfer Protocol:- which is used in sending large files

➔Simple Mail Transfer Protocol (SMTP):  helps transmit electronic mail over the internet.

➔Internet Message Access Protocol (IMAP):- retrieving email messages.

➔WWW, Whatsapp, and all communication channels and platforms.

Benefits of TCP/Ip Model

➔Industry-standard and open protocol with a scalable architecture.

➔flow control, Error control, and congestion control mechanisms.

➔Unique Identification-provide a unique Ip address making it identifiable over the network.


➔Network Optimization:-It is not designed for small networks.

➔Slow time of Handshake:-whenever a connection is made. TCP handshake between sender and receiver results in a connection slowdown.

TCP/IP  is a well-grounded stream delivery service that guarantees that all bytes received will be uniform and in the same order as those sent. Since packet transfer by many networks is not genuine, TCP attains this using a technique known as positive acknowledgment with retransmission.